1. Field of the Invention
The present invention relates generally to image processing, and in particular, to a method and apparatus for photographing a still image while recording a moving picture.
2. Description of the Related Art
Based on the development of communication technology, camera module technology and multimedia technology, a camera module is equipped in portable terminals so that moving pictures can be recorded and objects can be photographed to produce still images. In order to meet the expectations of the users, the service of photographing objects while recording moving pictures has been provided to portable terminals.
FIG. 1 is a flowchart illustrating a method of photographing an object while recording a moving picture in a conventional image device. Referring to FIG. 1, if a user requests a moving picture recording mode, the image device executes the moving picture recording mode in step 101. The image device operates a camera module according to pre-defined settings of the camera module in the moving picture recording mode in step 103 and displays on a display unit a preview image to be recorded. If the user requests to record a moving picture, the image device stores images displayed on the display unit in step 105. In this case, the image device compresses the moving picture data using a moving picture compression scheme, such as an MPEG (Motion Picture Editors Guild) scheme, and stores the compressed moving picture data.
The image device determines in step 107 if the user has input a request to photograph an object to produce a still image while recording the moving picture. If it is determined in step 107 that the user has not requested to photograph an object, the image device repeatedly performs step 107. If it is determined in step 107 that the user has input a request to photograph an object, the image device temporarily stops the recording and changes the operation mode of the camera module, according to pre-defined settings of the camera module, to a photographing mode in step 109. The image device photographs the object displayed on the display unit, compresses still image data produced by photographing the object using a still image compression scheme, such as a JPEG scheme, and stores the compressed still image data.
After photographing the objects, the image device changes the operation mode of the camera module, according to the pre-defined settings of the camera module, to the moving picture recording mode, records a moving picture displayed on the display unit, compresses moving picture data using the moving picture compression scheme, such as the MPEG scheme, and stores the compressed moving picture data in step 111. The image device determines in step 113 if the user has requested the termination of the recording. If it is determined in step 113 that the user has requested the termination of the recording, the image device stops storing the moving picture displayed on the display unit. If it is determined in step 113 that the user has not requested the termination of the recording, the image device continues to store the moving picture.
As illustrated in FIG. 1, the camera module changes image resolution settings of the preview image data when a still image is produced by photographing an object or when a moving picture is recorded, and generates preview image data according to the changed image resolution. For example, if the camera module supports the generation of still image data of 2 Mbytes, the camera module sets the image resolution to 800*600 while recording a moving picture, generates preview image data at the set image resolution, and outputs the generated preview image data. Thereafter, if the user inputs a request to photograph an object while recording the moving picture, the camera module sets the image resolution to 1600*1200, generates preview image data at the set image resolution, and outputs the generated preview image data. If the user terminates the photographing, the camera module sets the image resolution back to 800*600 generates preview image data at the set image resolution, and outputs the generated preview image data.
However, when the settings of the camera module are changed as illustrated in FIG. 1, the image device requires a delay time of around 1 second. Thus, when the user desires to photograph a current position of an object using the method illustrated in FIG. 1, the user may not be able to photograph the current position of the object due to the delay of the camera module.